A photocoupler, for example, which is a semiconductor device, includes a light emitting element and a light receiving element built-in and transmits a signal by an optical coupling. Therefore, the photocoupler is used for an isolation circuit that electrically insulates the primary side and the secondary side. Although the photocoupler has various uses, high insulating properties between the light emitting element on the primary side and the light receiving element on the secondary side are required in common. In addition, in a dual type product that includes two sets of a light emitting element and a light receiving element and has two transmission channels, it is necessary to suppress a crosstalk between channels.
For example, in a product in which the light receiving element side is connected to one frame, fabrication becomes easier by employing a method in which two sets of a light emitting element and a light receiving element are encapped by a one-body resin, but the crosstalk between channels cannot be suppressed. There is also a method in which two sets of a light emitting element and a light receiving element are individually encapped and are molded by a light blocking resin. The crosstalk can be suppressed by this method. However, a gap may be formed at the interface between the encap and the mold resin, and the dielectric breakdown voltage may be decreased. Thus, a semiconductor device in which the crosstalk between channels can be suppressed and the dielectric breakdown voltage can be increased and a method for manufacturing the same are required.